SYNR-406

Minimalist getter/parser for INI config files.
Changed Config from a refClass to an S4 class.  Changed parsing code to use nested lists and vectors.
SYNR-407 - login/logout has been implemented but not fully integrated
  - TODO: remove session tokens (almost) completely
  - TODO: change REST calls to only use HMAC auth
SYNR-530 - teamName requirement removed from submit
Changed REST calls to use only the API key.
Changed unit tests to no longer care about tokens and auth mode.
See SYNR-545
Code review style changes
Tests for login + general mocking code helpers

+ Fixed one error found via test
- Added a unit test for the ConfigParser.
- Slightly extended functionality of ConfigParser
Spelling error.
Put Tk/Terminal login logic into appropriate locations within the login logic.
Added another mocking function for exported/base that cannot be replaced.
Now locked functions can be intercepted.
SYNR-573

Read more from the config file.
+ Fix to login header check.
+ Added local logout before login. (like in Python)
+ Missing one set of brackets within ConfigParser logic.
+ Removed try-catch is .doWelcome() (it should fail if credentials are bad)
+ Changed the way keys to cached to include the endpoint (so that repo and staging can be kept)
Minor change
+ suppression option for "Goodbye" message
Fixed tests that were broken by previous change to login code
Reverting change to how rememberMe flag works.  No need to differentiate between auth endpoints.
Merge branch 'develop' of https://github.com/Sage-Bionetworks/rSynapseClient into login_logout
Merge pull request #98 from kaysoky/login_logout

SYNR-406, SYNR-407, SYNR-530, SYNR-565